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[ARCHIVED THREAD] - Loaded PMags won't seat on closed bolt

Posted: 9/14/2020 5:56:01 AM EST

I have 12 30rd pmags that have been charged/loaded for several years. I THINK a couple of them had no lids on them.

IN any case, 2 of the mags refuse to seat under any pressure with a closed bolt.

What caused this? Would long term storage with no lid cause this? It actually looks like the second round is edging up, not maintaining the angle.

Seats fine with bolt open; did not try to cycle.

Am I throwing out 2 mags in the trash? How can this be avoided if it's not just the lid?

Posted: 9/13/2020 12:34:12 PM EST

[#1]

Won't seat even with a slap?

Also, just for kicks, empty the mag and count rounds.

Posted: 9/13/2020 12:36:36 PM EST

[#2]

you can throw them out in the trash if you want, they're your mags. me, I would just load 28 rounds in them

Posted: 9/13/2020 12:43:55 PM EST

[#3]

Try 28-29 rounds,i bet they seat then

Posted: 9/13/2020 12:45:40 PM EST

[#4]

How many rounds are loaded in the mags? Can you load another round?

As with any double stack magazine for any firearm, if you are loaded to absolute maximum capacity, it will likely not have enough room be able to insert the mag on a closed bolt.

Due to people whining over this basic fact of physics with USGI type "30 round" magazines, which are normally loaded to 28 or 29, "30 round" PMags were made larger so will typically hold 31 rounds. But if you load 31, again you are limited by reality that it won't fit with a closed bolt.

Posted: 9/13/2020 12:45:57 PM EST

[#5]

they seat with 26 rounds. Tried one at a time.

As a matter of fact I may have loaded 31 in one of them. . .s

Posted: 9/13/2020 12:46:50 PM EST

[#6]

What's the caliber? Ammo type? I have a few 300BLK Magpuls and some brands of subs refuse to seat on a closed bolt, while supers will seat just fine. The size and shape of the projectiles can apparently make a huge difference.

Posted: 9/13/2020 1:27:35 PM EST

[#7]

Usually is the 31 issue. Notice which side your top round is on when you load 30. Then, you can do a quick check if you are loading or have a problem with seating.

Posted: 9/13/2020 1:45:52 PM EST

[#8]

Quote History

Quoted:
As with any double stack magazine for any firearm, if you are loaded to absolute maximum capacity, it will likely not have enough room be able to insert the mag on a closed bolt.

View Quote

One of Magpul's design goals when they developed the PMAG was specifically to allow a little extra room for the spring to compress so you could load the full magazine on a closed bolt. They wanted to alleviate the need to download by a round or two in order to reliably seat the magazine on a closed bolt. If a regular PMAG 30 isn't locking in place on a closed bolt, then something is off.

OP, if you confirm that the magazines have only 30 rounds in them (and not an extra squeezed in there), I would contact Magpul. They will likely ask you to send those two mags back for testing and will send you free replacements. Were these mags brand new when you first loaded them?

The other option is to download a round or two and shoot them a few times to see if the spring breaks in a little and allows you to seat them when full loaded.

Posted: 9/13/2020 1:51:18 PM EST

[#9]

Quote History

Quoted:
you can throw them out in the trash if you want, they're your mags. me, I would just load 28 rounds in them

View Quote

This.

As an alternative, take a fully loaded mag and try putting one more round in it.

This is the equivalent of trying to seat a loaded mag on a closed bolt...you have to push the top round down with a) enough force and b) far enough to seat.

Sometimes, it’s just not going to happen.

Posted: 9/13/2020 6:07:07 PM EST

[#10]

This will fix the problem.

https://botach.com/lancer-l5awm-5-56mm-30rd-magazines-black/

Posted: 9/13/2020 6:12:16 PM EST

[#11]

Quote History

Quoted:
you can throw them out in the trash if you want, they're your mags. me, I would just load 28 rounds in them

View Quote

^^^^This^^^^

Posted: 9/13/2020 6:15:49 PM EST

[#12]

Quote History

Quoted:
The other option is to download a round or two and shoot them a few times to see if the spring breaks in a little and allows you to seat them when full loaded.

View Quote

^^^^Also this^^^^

Posted: 9/13/2020 6:17:20 PM EST

[#13]

As stated above, download a round or two and it will seat.

Posted: 9/13/2020 6:34:07 PM EST

[#14]

OP ever since the United States Marine Corps taught me in the 90's to only load 28 in a 30 round magazine that's all I know and all I do and it worked then and it works now.

Posted: 9/13/2020 10:00:22 PM EST

[#15]

Quoted:

One of Magpul's design goals when they developed the PMAG was specifically to allow a little extra room for the spring to compress so you could load the full magazine on a closed bolt. They wanted to alleviate the need to download by a round or two in order to reliably seat the magazine on a closed bolt. If a regular PMAG 30 isn't locking in place on a closed bolt, then something is off.

OP, if you confirm that the magazines have only 30 rounds in them (and not an extra squeezed in there), I would contact Magpul. They will likely ask you to send those two mags back for testing and will send you free replacements. Were these mags brand new when you first loaded them?

wasThe other option is to download a round or two and shoot them a few times to see if the spring breaks in a little and allows you to seat them when full loaded.

View Quote

This

the original Aluminum magazine was designed by the Colt Engineers, to hold 30 rds... because that is what the Army asked them to do...
They never factored in the need to have some extra space to allow for the 30 rds to compress a bit more when trying to seat a full magazine on a closed bolt.

Remember, back in the day, the thought was..."Why would they need to put a 30 rd mag in a closed bolt, the bolt would be locked to the rear (cause it was empty)"
-
We have learned a lot since then, and the need to top off the gun with a fresh reload, necessitated that...So the down loading to 28-29 rds was born.

I still do it, because it works, but the PMAG's were designed with that in mind.

Posted: 9/13/2020 11:16:52 PM EST

[#16]

It has been said before and it bears repeating, PMAGs were designed to be able to load the entire 30 rounds and seat easily on a closed bolt.

If that's not working then there's a problem. Regardless of whether you actually want to load 30 rounds or not, this indicates there could be something off that could impact general function.

Posted: 9/13/2020 11:32:09 PM EST

[#17]

The internet will tell me I’m a pog bitch for this but i do 28 rounds per mag

Tac reloads are the norm. Firing till dry is abnormal. Therefore I need to seat mags most often on a closed bolt, so 28 rounds (even for pmags) per mag it is for me.

Posted: 9/14/2020 1:55:54 AM EST

[#18]

I noticed on my P-Mags will load 31 rds, But would seat with bolt closed. Down load to 30rds. LOL

Posted: 9/14/2020 1:57:09 AM EST

[#19]

I noticed on my P-Mags will load 31 rds, But would seat with bolt closed. Down load to 30rds. LOL No Problem with 30rounds.

Posted: 9/14/2020 2:23:39 AM EST

[#20]

I have a number of Gen 2 Pmag that I use at work. They are loaded to 30 rounds. Occasionally the 2nd round down in the stack will shift slightly laterally to the outside of the magazine and make it very difficult to seat on a closed bolt. If I press down on the rounds the 2nd one will go back into its proper position and the magazine will seat easily. At the beginning of each shift I do this as PM and once in a while while I’m out wandering around. I believe that the magazines being subjected to being bounced around while driving off road and when I’m out cutting on foot causes this. With a proper “push / pull” loading procedure I can seat the magazine even when the 2nd round has shifted but it can be very difficult.

Posted: 9/14/2020 5:56:01 AM EST

[#21]

Topic Moved

Posted: 9/14/2020 7:00:41 AM EST

[#22]

I’m sure at least one of the two had 31 roundS

Thanks guys.

Posted: 9/14/2020 7:55:20 AM EST

[#23]

Pmags should have the top round on the right, when viewed from the rear at 30 rounds.

Posted: 9/14/2020 8:27:10 AM EST

[#24]

load 28

Posted: 9/14/2020 11:11:29 AM EST

[#25]

Quote History

Quoted:
I have a number of Gen 2 Pmag that I use at work. They are loaded to 30 rounds. Occasionally the 2nd round down in the stack will shift slightly laterally to the outside of the magazine and make it very difficult to seat on a closed bolt. If I press down on the rounds the 2nd one will go back into its proper position and the magazine will seat easily. At the beginning of each shift I do this as PM and once in a while while I’m out wandering around. I believe that the magazines being subjected to being bounced around while driving off road and when I’m out cutting on foot causes this. With a proper “push / pull” loading procedure I can seat the magazine even when the 2nd round has shifted but it can be very difficult.

View Quote

This is good knowledge.

Posted: 9/14/2020 10:15:41 PM EST

[#26]

Quote History

Quoted:
I have a number of Gen 2 Pmag that I use at work. They are loaded to 30 rounds. Occasionally the 2nd round down in the stack will shift slightly laterally to the outside of the magazine and make it very difficult to seat on a closed bolt. If I press down on the rounds the 2nd one will go back into its proper position and the magazine will seat easily. At the beginning of each shift I do this as PM and once in a while while I’m out wandering around. I believe that the magazines being subjected to being bounced around while driving off road and when I’m out cutting on foot causes this. With a proper “push / pull” loading procedure I can seat the magazine even when the 2nd round has shifted but it can be very difficult.

View Quote

I picked up a habit from my VietNam combat vet uncles when shooting any magazine fed rifle (I use it on pistols as well). Slap the spine of the mag into your palm and then the bottom against a hard surface (kevlar, rock, bench, etc). This habit followed me into the Army as well as to today. This helps with the situation that you are describing of the shifting round(s).

As far as the OP, I'm pretty sure that you loaded 1 too many in those mags. It has happened to me with aluminum mags with the newer followers. With black or green followers and an Up Lula, I can tell the count by feel. Mags with new style followers (where they reversed the casing mold side), I have to do a count otherwise I can get an extra round in. I don't know if it is follower related per se', but all generations of my aluminum mags spec the same dimension wise.....so it has to be either the follow or spring.

Posted: 9/15/2020 10:02:19 PM EST

[#27]

If they won't seat at 30rd with a good slap I'd send em back to Magpul for replacement.

Don't load 31

Posted: 9/23/2020 4:51:21 PM EST

[#28]

looks like i'm preaching to the choir here but always been told to load 30rd mags to 28 or 29 rds to avoid this issue

Posted: 9/26/2020 6:32:31 AM EST

[#29]

I've got about 100,000rds down range and run multiple ranges a week with troops using 30 rd mags. Never an issue with 30 rds being loaded in a 30 rd mag unless the mag was dented/damaged. Then the mag gets stomped or used as a target. Now load them with 31 rds and mag will not lock in on a closed bolt.

CD

[ARCHIVED THREAD] - Loaded PMags won't seat on closed bolt

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